The mechanisms of partial dislocation mobility in the {111} glide system were studied in detail by using effective new relaxation and sampling algorithms, together with the Stillinger-Weber empirical interatomic potential and simulation models which involved up to 90000 atoms. Low-energy pathways for the generation, annihilation and motion of in-core defects of the 30 partial dislocation were identified. Particular attention was paid to the individual left-hand and right-hand components of a double-kink, an antiphase defect, and various kink plus antiphase defect complexes. It was shown that the underlying mechanisms of these defect reactions fell into 3 distinct categories which were characterized by processes of bond-breaking, bond-switching, and bond-exchange, respectively. The quantitative results revealed a marked left-right asymmetry in the kinetics of kink propagation, and a strong binding of antiphase defects to kinks. These had not previously been recognized. The present work also demonstrated the feasibility of an atomistic approach to the modelling of the kinetic processes which underlay dislocation mobility in crystals with a high Peierls barrier.

V.V.Bulatov, S.Yip, A.S.Argon: Philosophical Magazine A, 1995, 72[2], 453-96